Microscopy is among the oldest applications of optical science and remains one of the most widely used optical technologies. In spite of impressive results obtained by fluorescent microscopy, exceeding the classical diffraction limit, non-fluorescent transmission/reflection microscopy remains an important field of modern research.
Traditional microscopy approaches are restricted in resolution by the low-pass filter characteristics of the optical system. As is well-known, the bandpass of a lens is a circle of radius NA/λ where NA is the numerical aperture of the lens and λ is the optical wavelength. These limitations are discussed in many texts, for example, in the text entitled “Principles of Optics” by Born and Wolff (Sixth Ed., 1980, Cambridge University Press), and in the text entitled “Introduction to Fourier Optics” by J. W. Goodman (2005, Roberts and Co.).
Thus, there is a need to overcome these and other problems of the prior art and to provide an imaging interferometric microscope to extend the collected spatial frequencies for improving the image, and methods for its use.